Technical metadata - link aprture & focal length

[Arnold Wiegert]

Just found Photini and think it will be very useful & helpful for my needs. Thank you for making it available.

In testing with a small number of existing images as a test, I get a notice about "Adjust image aperture & focal length ...."

If I don't 'adjust', the dialog pops up whenever I display the tech data, if I allow the 'adjustment', I see no difference in the displayed data before & after.

I have searched the 'net for this message, but did not find any explanation for why I am seeing it nor what it will do.

A second question, but of much less importance:

which image types are supported and which allow adding the thumbnails. for those types which do not allow inclusion in the image, will a sidecar file be created?

TIA

[Jim Easterbrook]

On 01/09/2024 21:28, Arnold Wiegert wrote:
> In testing with a small number of existing images as a test, I get a
> notice about "Adjust image aperture & focal length ...."
> If I don't 'adjust', the dialog pops up whenever I display the tech
> data, if I allow the 'adjustment', I see no difference in the displayed
> data before & after.

I added this functionality because I use some lenses and telescopes with
an adapter that tells my camera the lens is 50 mm, f/1.8 regardless of
what lens I'm actually using. When I set the lens model to 500 mm, f/6.3
(for example) then the focal length and aperture are changed from 50 mm
and f/1.8 to the correct values for the lens.

The dialog shouldn't be shown if no adjustment is needed so you might
have found a bug there. If you can extract the metadata (before
Photini's modified it) and send me the file it might be useful.

The command 'exiv2 ex problem_file.jpg' will extract the metadata from
problem_file.jpg and put it in a '.exv' file that I can use for testing.

> A second question, but of much less importance:
> which image types are supported and which allow adding the thumbnails.
> for those types which do not allow inclusion in the image, will a
> sidecar file be created?

The supported image types for reading and writing metadata depend on
libexiv2.
https://dev.exiv2.org/projects/exiv2/wiki/Supported_image_formats

The supported image types for thumbnail recreation depend on Pillow or
Qt or ffmpeg.
https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html
https://doc-snapshots.qt.io/qt6-6.2/qimage.html#reading-and-writing-image-files

A sidecar file will always be created if any metadata, including the
thumbnail, cannot be stored in the image file.

--
Jim Easterbrook <http://www.jim-easterbrook.me.uk/>

[Arnold Wiegert]

Thank you, Jim

From my limited testing, it seems the problem with the lens data shows only for the pictures taken with one camera.

I'll attach the /exv file for your testing.

FWIW, it might be useful/interesting to be able to open and inspect such 'empty' data files generated by exiv2 & mie from Exiftool.

It is my understanding that those are simply image files with the 'image' carved out.

Arnold

--
You received this message because you are subscribed to the Google Groups "photini" group.
To unsubscribe from this group and stop receiving emails from it, send an email to photini+u...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/photini/4f587515-8d5f-4ca5-9653-9c167c385fee%40jim-easterbrook.me.uk.

[Jim Easterbrook]

On 02/09/2024 18:40, Arnold Wiegert wrote:
> From my limited testing, it seems the problem with the lens data shows
> only for the pictures taken with one camera.
> I'll attach the /exv file for your testing.

Thanks for the file - it definitely shouldn't trigger the dialog as
there isn't any proper info about the lens specification, just its name.
I'll fix this in the next Photini release.

> FWIW, it might be useful/interesting to be able to open and inspect such
> 'empty' data files generated by exiv2 & mie from Exiftool.
> It is my understanding that those are simply image files with the
> 'image' carved out.

That's something to take up with the author of Exiftool. You can inspect
them with exiv2 though.

[Jim Easterbrook]

On 02/09/2024 18:51, Jim Easterbrook wrote:
>
> I'll fix this in the next Photini release.

If you want to fix it now, find your installed copy of
photini/technical.py and make the change to line 900 shown here:
https://github.com/jim-easterbrook/Photini/pull/265/commits/4b3235892604c4cac23ce4c841302443c82c6e30

(The file location will depend on how you've installed Photini. 'pip
show photini' will show you.)

[Arnold Wiegert]

Thank you; making the change fixed the pop-up.

Arnold

--
You received this message because you are subscribed to the Google Groups "photini" group.
To unsubscribe from this group and stop receiving emails from it, send an email to photini+u...@googlegroups.com.

To view this discussion on the web, visit https://groups.google.com/d/msgid/photini/c52a4ced-000e-4caf-83ea-d451aa623e46%40jim-easterbrook.me.uk.